For trim and doors, start with 1 gallon (3.8 L) of trim paint for every 600 sq feet of floor space. Purchase more at the store if/when needed. Trim is something that is difficult to calculate exactly, and it is more time-efficient to simply start with less than you need, and go buy more after you have used up the first round of paint and determined how much you will need to finish by seeing how much you have painted so far, compared to the gallons used.
While vinyl siding salespeople claim it never needs to be painted, it does lose its color strength over time, and the degree of fading can vary depending on which sides get the most exposure to sunlight. Perhaps it still hasn’t faded, but you don’t like the color much. You can’t go any darker than its current color, though, because the siding is designed to absorb only so much heat, and a darker color could cause it to buckle. Vinyl paint is available in many colors. Brush painting and roll painting vinyl siding costs $43 per 100 sq. ft., and spray painting costs $34 per 100 sq. ft. House Painting Denver Colorado